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Diffstat (limited to 'ICSharpCode.Decompiler/Ast/Transforms/IntroduceQueryExpressions.cs')
-rw-r--r-- | ICSharpCode.Decompiler/Ast/Transforms/IntroduceQueryExpressions.cs | 295 |
1 files changed, 0 insertions, 295 deletions
diff --git a/ICSharpCode.Decompiler/Ast/Transforms/IntroduceQueryExpressions.cs b/ICSharpCode.Decompiler/Ast/Transforms/IntroduceQueryExpressions.cs deleted file mode 100644 index 0da56fe9..00000000 --- a/ICSharpCode.Decompiler/Ast/Transforms/IntroduceQueryExpressions.cs +++ /dev/null @@ -1,295 +0,0 @@ -// Copyright (c) 2011 AlphaSierraPapa for the SharpDevelop Team -// -// Permission is hereby granted, free of charge, to any person obtaining a copy of this -// software and associated documentation files (the "Software"), to deal in the Software -// without restriction, including without limitation the rights to use, copy, modify, merge, -// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons -// to whom the Software is furnished to do so, subject to the following conditions: -// -// The above copyright notice and this permission notice shall be included in all copies or -// substantial portions of the Software. -// -// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, -// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR -// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE -// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR -// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER -// DEALINGS IN THE SOFTWARE. - -using System; -using System.Diagnostics; -using System.Linq; -using ICSharpCode.NRefactory.CSharp; - -namespace ICSharpCode.Decompiler.Ast.Transforms -{ - /// <summary> - /// Decompiles query expressions. - /// Based on C# 4.0 spec, §7.16.2 Query expression translation - /// </summary> - public class IntroduceQueryExpressions : IAstTransform - { - readonly DecompilerContext context; - - public IntroduceQueryExpressions(DecompilerContext context) - { - this.context = context; - } - - public void Run(AstNode compilationUnit) - { - if (!context.Settings.QueryExpressions) - return; - DecompileQueries(compilationUnit); - // After all queries were decompiled, detect degenerate queries (queries not property terminated with 'select' or 'group') - // and fix them, either by adding a degenerate select, or by combining them with another query. - foreach (QueryExpression query in compilationUnit.Descendants.OfType<QueryExpression>()) { - QueryFromClause fromClause = (QueryFromClause)query.Clauses.First(); - if (IsDegenerateQuery(query)) { - // introduce select for degenerate query - query.Clauses.Add(new QuerySelectClause { Expression = new IdentifierExpression(fromClause.Identifier) }); - } - // See if the data source of this query is a degenerate query, - // and combine the queries if possible. - QueryExpression innerQuery = fromClause.Expression as QueryExpression; - while (IsDegenerateQuery(innerQuery)) { - QueryFromClause innerFromClause = (QueryFromClause)innerQuery.Clauses.First(); - if (fromClause.Identifier != innerFromClause.Identifier) - break; - // Replace the fromClause with all clauses from the inner query - fromClause.Remove(); - QueryClause insertionPos = null; - foreach (var clause in innerQuery.Clauses) { - query.Clauses.InsertAfter(insertionPos, insertionPos = clause.Detach()); - } - fromClause = innerFromClause; - innerQuery = fromClause.Expression as QueryExpression; - } - } - } - - bool IsDegenerateQuery(QueryExpression query) - { - if (query == null) - return false; - var lastClause = query.Clauses.LastOrDefault(); - return !(lastClause is QuerySelectClause || lastClause is QueryGroupClause); - } - - void DecompileQueries(AstNode node) - { - QueryExpression query = DecompileQuery(node as InvocationExpression); - if (query != null) - node.ReplaceWith(query); - for (AstNode child = (query ?? node).FirstChild; child != null; child = child.NextSibling) { - DecompileQueries(child); - } - } - - QueryExpression DecompileQuery(InvocationExpression invocation) - { - if (invocation == null) - return null; - MemberReferenceExpression mre = invocation.Target as MemberReferenceExpression; - if (mre == null) - return null; - switch (mre.MemberName) { - case "Select": - { - if (invocation.Arguments.Count != 1) - return null; - string parameterName; - Expression body; - if (MatchSimpleLambda(invocation.Arguments.Single(), out parameterName, out body)) { - QueryExpression query = new QueryExpression(); - query.Clauses.Add(new QueryFromClause { Identifier = parameterName, Expression = mre.Target.Detach() }); - query.Clauses.Add(new QuerySelectClause { Expression = body.Detach() }); - return query; - } - return null; - } - case "GroupBy": - { - if (invocation.Arguments.Count == 2) { - string parameterName1, parameterName2; - Expression keySelector, elementSelector; - if (MatchSimpleLambda(invocation.Arguments.ElementAt(0), out parameterName1, out keySelector) - && MatchSimpleLambda(invocation.Arguments.ElementAt(1), out parameterName2, out elementSelector) - && parameterName1 == parameterName2) - { - QueryExpression query = new QueryExpression(); - query.Clauses.Add(new QueryFromClause { Identifier = parameterName1, Expression = mre.Target.Detach() }); - query.Clauses.Add(new QueryGroupClause { Projection = elementSelector.Detach(), Key = keySelector.Detach() }); - return query; - } - } else if (invocation.Arguments.Count == 1) { - string parameterName; - Expression keySelector; - if (MatchSimpleLambda(invocation.Arguments.Single(), out parameterName, out keySelector)) { - QueryExpression query = new QueryExpression(); - query.Clauses.Add(new QueryFromClause { Identifier = parameterName, Expression = mre.Target.Detach() }); - query.Clauses.Add(new QueryGroupClause { Projection = new IdentifierExpression(parameterName), Key = keySelector.Detach() }); - return query; - } - } - return null; - } - case "SelectMany": - { - if (invocation.Arguments.Count != 2) - return null; - string parameterName; - Expression collectionSelector; - if (!MatchSimpleLambda(invocation.Arguments.ElementAt(0), out parameterName, out collectionSelector)) - return null; - LambdaExpression lambda = invocation.Arguments.ElementAt(1) as LambdaExpression; - if (lambda != null && lambda.Parameters.Count == 2 && lambda.Body is Expression) { - ParameterDeclaration p1 = lambda.Parameters.ElementAt(0); - ParameterDeclaration p2 = lambda.Parameters.ElementAt(1); - if (p1.Name == parameterName) { - QueryExpression query = new QueryExpression(); - query.Clauses.Add(new QueryFromClause { Identifier = p1.Name, Expression = mre.Target.Detach() }); - query.Clauses.Add(new QueryFromClause { Identifier = p2.Name, Expression = collectionSelector.Detach() }); - query.Clauses.Add(new QuerySelectClause { Expression = ((Expression)lambda.Body).Detach() }); - return query; - } - } - return null; - } - case "Where": - { - if (invocation.Arguments.Count != 1) - return null; - string parameterName; - Expression body; - if (MatchSimpleLambda(invocation.Arguments.Single(), out parameterName, out body)) { - QueryExpression query = new QueryExpression(); - query.Clauses.Add(new QueryFromClause { Identifier = parameterName, Expression = mre.Target.Detach() }); - query.Clauses.Add(new QueryWhereClause { Condition = body.Detach() }); - return query; - } - return null; - } - case "OrderBy": - case "OrderByDescending": - case "ThenBy": - case "ThenByDescending": - { - if (invocation.Arguments.Count != 1) - return null; - string parameterName; - Expression orderExpression; - if (MatchSimpleLambda(invocation.Arguments.Single(), out parameterName, out orderExpression)) { - if (ValidateThenByChain(invocation, parameterName)) { - QueryOrderClause orderClause = new QueryOrderClause(); - InvocationExpression tmp = invocation; - while (mre.MemberName == "ThenBy" || mre.MemberName == "ThenByDescending") { - // insert new ordering at beginning - orderClause.Orderings.InsertAfter( - null, new QueryOrdering { - Expression = orderExpression.Detach(), - Direction = (mre.MemberName == "ThenBy" ? QueryOrderingDirection.None : QueryOrderingDirection.Descending) - }); - - tmp = (InvocationExpression)mre.Target; - mre = (MemberReferenceExpression)tmp.Target; - MatchSimpleLambda(tmp.Arguments.Single(), out parameterName, out orderExpression); - } - // insert new ordering at beginning - orderClause.Orderings.InsertAfter( - null, new QueryOrdering { - Expression = orderExpression.Detach(), - Direction = (mre.MemberName == "OrderBy" ? QueryOrderingDirection.None : QueryOrderingDirection.Descending) - }); - - QueryExpression query = new QueryExpression(); - query.Clauses.Add(new QueryFromClause { Identifier = parameterName, Expression = mre.Target.Detach() }); - query.Clauses.Add(orderClause); - return query; - } - } - return null; - } - case "Join": - case "GroupJoin": - { - if (invocation.Arguments.Count != 4) - return null; - Expression source1 = mre.Target; - Expression source2 = invocation.Arguments.ElementAt(0); - string elementName1, elementName2; - Expression key1, key2; - if (!MatchSimpleLambda(invocation.Arguments.ElementAt(1), out elementName1, out key1)) - return null; - if (!MatchSimpleLambda(invocation.Arguments.ElementAt(2), out elementName2, out key2)) - return null; - LambdaExpression lambda = invocation.Arguments.ElementAt(3) as LambdaExpression; - if (lambda != null && lambda.Parameters.Count == 2 && lambda.Body is Expression) { - ParameterDeclaration p1 = lambda.Parameters.ElementAt(0); - ParameterDeclaration p2 = lambda.Parameters.ElementAt(1); - if (p1.Name == elementName1 && (p2.Name == elementName2 || mre.MemberName == "GroupJoin")) { - QueryExpression query = new QueryExpression(); - query.Clauses.Add(new QueryFromClause { Identifier = elementName1, Expression = source1.Detach() }); - QueryJoinClause joinClause = new QueryJoinClause(); - joinClause.JoinIdentifier = elementName2; // join elementName2 - joinClause.InExpression = source2.Detach(); // in source2 - joinClause.OnExpression = key1.Detach(); // on key1 - joinClause.EqualsExpression = key2.Detach(); // equals key2 - if (mre.MemberName == "GroupJoin") { - joinClause.IntoIdentifier = p2.Name; // into p2.Name - } - query.Clauses.Add(joinClause); - query.Clauses.Add(new QuerySelectClause { Expression = ((Expression)lambda.Body).Detach() }); - return query; - } - } - return null; - } - default: - return null; - } - } - - /// <summary> - /// Ensure that all ThenBy's are correct, and that the list of ThenBy's is terminated by an 'OrderBy' invocation. - /// </summary> - bool ValidateThenByChain(InvocationExpression invocation, string expectedParameterName) - { - if (invocation == null || invocation.Arguments.Count != 1) - return false; - MemberReferenceExpression mre = invocation.Target as MemberReferenceExpression; - if (mre == null) - return false; - string parameterName; - Expression body; - if (!MatchSimpleLambda(invocation.Arguments.Single(), out parameterName, out body)) - return false; - if (parameterName != expectedParameterName) - return false; - - if (mre.MemberName == "OrderBy" || mre.MemberName == "OrderByDescending") - return true; - else if (mre.MemberName == "ThenBy" || mre.MemberName == "ThenByDescending") - return ValidateThenByChain(mre.Target as InvocationExpression, expectedParameterName); - else - return false; - } - - /// <summary>Matches simple lambdas of the form "a => b"</summary> - bool MatchSimpleLambda(Expression expr, out string parameterName, out Expression body) - { - LambdaExpression lambda = expr as LambdaExpression; - if (lambda != null && lambda.Parameters.Count == 1 && lambda.Body is Expression) { - ParameterDeclaration p = lambda.Parameters.Single(); - if (p.ParameterModifier == ParameterModifier.None) { - parameterName = p.Name; - body = (Expression)lambda.Body; - return true; - } - } - parameterName = null; - body = null; - return false; - } - } -} |